With advancement of a radio access method and a radio network for cellular mobile communication (hereinafter referred to as Long Term Evolution (LTE) or “Evolved Universal Terrestrial Radio Access (EUTRA),” the 3rd Generation Partnership Project (3GPP) has been studying a radio access method and a radio network (hereinafter referred to as “Long Term Evolution-Advanced (LTE-A)” or “Advanced EUTRA”) for achieving further high-speed data communication utilizing wider range frequencies.
LTE uses an orthogonal frequency division multiplexing (OFDM) scheme which is multi-carrier transmission for a downlink. For an uplink, LTE uses a single carrier communication scheme of a DFT (discrete Fourier transform)—Spread OFDM scheme which is single carrier transmission. In contrast, it is proposed that LTE-A uses the OFDM scheme for the downlink, and newly uses, for the uplink, the OFDM scheme, a Clustered DFT-Spread OFDM scheme, and a N*DFT-Spread OFDM scheme which are the multi-carrier communication schemes, in addition to the DFT-Spread OFDM scheme, (see Non-patent Document 1 below).
For the downlink of radio communication from a base station apparatus to a mobile station apparatus, LTE uses a broadcast channel (Physical Broadcast Channel; PBCH), a downlink control channel (Physical Downlink Control Channel; PDCCH), a downlink shared channel (Physical Downlink Shared Channel; PDSCH), a multicast channel (Physical Multicast Channel; PMCH), a control format indicator channel (Physical Control Format Indicator Channel; PCFICH), and an HARQ indicator channel (Physical Hybrid ARQ Indicator Channel; PHICH). For the uplink of radio communication from the mobile station apparatus to the base station apparatus, LTE uses an uplink shared channel (PUSCH: Physical Uplink Shared Channel), an uplink control channel (PUCCH: Physical Uplink Control Channel), and a random access channel (PRACH: Physical Random Access Channel).
Meanwhile, LTE-A is required to have compatibility with LTE, that is, to enable a base station apparatus supporting LTE-A to communicate with both types of mobile station apparatuses supporting LTE-Advanced and mobile station apparatuses supporting LTE, and to enable a mobile station apparatus supporting LTE-A to perform radio communication with base stations supporting either of LTE-A and LTE. Thus, studies have been made on use of the same channel structure as in LTE. In addition, while a frequency band used in a general mobile communication system is contiguous, there is proposed utilization of multiple contiguous/non-contiguous frequency bands (hereinafter, referred to as “carrier components (CCs)” or “component carriers” (CCs)), as a single frequency band (wide frequency band) (frequency band aggregation: sometimes referred to as spectrum aggregation, carrier aggregation, frequency aggregation, or the like) (see Non-patent Document 2 below).
Further, studies have been made on configuring a downlink control channel (PDCCH) for each carrier component in the downlink in LTE-A. By using the downlink control channel (PDCCH), a base station transmits a downlink grant (DL grant) for each carrier component in the downlink, the downlink grant being control information including information indicating radio resource allocation (RA) of a downlink shared channel (PDSCH). By using the downlink control channel (PDCCH), the base station also transmits an uplink grant (UL grant) for each carrier component in the uplink, the uplink grant being control information including a region indicating radio resource allocation (RA) of the uplink shared channel (PUSCH) in the carrier component in the uplink.
Another proposal for LTE-A is that identities for identifying carrier components corresponding to the uplink grant and the downlink grant are included in the uplink grant and the downlink grant, respectively, and that a base station apparatus transmits an uplink grant and a downlink grant addressed to the same mobile station apparatus by using multiple downlink control channels (PDCCHs) on the same carrier component in the downlink (see Non-patent Document 3 and Non-patent Document 4 below).
The uplink grant and the downlink grant in LTE are constituted of information for the uplink shared channel (PUSCH) and the downlink shared channel (PDSCH), such as information on modulation schemes, information on coding schemes, and information on HARQ, in addition to the information indicating the radio resource allocation (RA). In addition, the mobile station apparatus is identified by using a 16-bit mobile station identity (also referred to as a radio network temporary identity; RNTI or a user equipment identity; UE ID) which is uniquely identifiable in the base station apparatus and included in the uplink grant and the downlink grant.
The following are cited as related technical documents.